Level 251 solution

Solver-verified route

1. Place Piece 1 across column 2 row 6, column 3 row 6, column 4 row 6.
2. Place Piece 2 at column 3, row 5.
3. Place Piece 5 at column 3, row 7.
4. Place Piece 3 across column 7 row 6, column 6 row 7, column 7 row 7.
5. Place Piece 4 across column 8 row 7, column 7 row 8, column 8 row 8.
6. Place Piece 6 across column 6 row 4, column 6 row 5, column 6 row 6.
7. Place Piece 7 across column 4 row 4, column 5 row 4, column 4 row 5, column 5 row 5.

Part of the "Master columns" chapter. The solver certified 1000+ solving lines with 87% of in-between placements being dead ends, for a difficulty score of 19.6 (grade 5 of 5).